This invention is in the field of mast systems for supporting, conveying and/or hoisting booms, as well as derricks and personnel lift equipment. In particular, the invention addresses the mounting of masts using mast supports.
Construction works in industrial or municipal plants frequently require the hoisting, conveyance and/or placement of materials, equipment and personnel for construction of facilities or plant operation. Properly constructed and installed, boom and personnel lift systems offer a safe, cost effective and efficient method of accomplishing these tasks. Mast systems (either tubular masts or lattice towers) are currently used to allow boom, crane and personnel lift equipment to be installed at an elevated position, typically 10–250 feet above grade elevation or at the top of a building or structure. The minimum size of the mast, both in diameter and in length, is dictated by a variety of loads on the mast, including the load from the supported equipment, operating loads (e.g., material being hoisted) which generate an overturning moment, vertical and horizontal loads, wind and snow loads and other vertical and horizontal loads. In order to minimize the load reactions at the mast anchorage points and on the structure to which the mast is anchored, it is desirable to use the smallest and lightest mast allowed by engineering requirements for the particular application.
It is known to provide mounting systems for masts by attaching supporting trusses to vertical walls. Previous systems, however, were specially designed to accommodate a single mast size. Thus, if a construction firm owned more than one mast, it was necessary for the firm to purchase multiple mounting systems in order to accommodate each differently sized mast. If it became desirable to change mast sizes during the job, the mounting system would need to be changed. This usually required unbolting the mounting system from the wall in order to allow for the changing of the mast.